Botulinum neurotoxin and other treatments for fissure-in-ano and pelvic floor disorders

Arch Expansion Efficiency of Clear Aligner on Patients with Mixed Dentition Using 3ship Digital Oral Scanner

The aim of this study to evaluate the maxillary and mandibular arch expansion efficiency of clear aligner. A total of 15 patients aged between 8–11 who were admitted from January 2020 to December 2021. The 3ship digital oral scanner was used to establish a digital oral model for the patients before and after the correction. The three-dimensional model before and after correction was established by ClinCheck software to measure and record the width of each tooth position and evaluate the efficiency of arch expansion. The dental arch width was greater after correction of the width between the maxillary and maxillary canines, the width between the first premolars, the width between the second premolars, and the width between the first molars, showing statistically significant differences (P <0.05). The arch expansion efficiency in the maxillary canine area > the maxillary first premolar efficiency > the maxillary second premolar efficiency > the maxillary first molar efficiency. Through the linear regression equation, the preset expansion amount of each tooth position was reasonably predicted.Taken together our data suggested that the clear aligner efficiency can be improved by adding accessories and torque in the base bone range when necessary.

ACG Clinical Guidelines: Management of Benign Anorectal Disorders

Benign anorectal disorders of structure and function are common in clinical practice. These guidelines summarize the preferred approach to the evaluation and management of defecation disorders, proctalgia syndromes, hemorrhoids, anal fissures, and fecal incontinence in adults and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was assessed using the Grading of Recommendations Assessment, Development and Evaluation process. When the evidence was not appropriate for Grading of Recommendations Assessment, Development and Evaluation, we used expert consensus to develop key concept statements. These guidelines should be considered as preferred but are not the only approaches to these conditions.

Gastrointestinal Uses of Botulinum Toxin

Botulinum toxin (BT), one of the most powerful inhibitors that prevents the release of acetylcholine from nerve endings, represents an alternative therapeutic approach for "spastic" disorders of the gastrointestinal tract such as achalasia, gastroparesis, sphincter of Oddi dysfunction, chronic anal fissures, and pelvic floor dyssynergia.BT has proven to be safe and this allows it to be a valid alternative in patients at high risk of invasive procedures but long-term efficacy in many disorders has not been observed, primarily due to its relatively short duration of action. Administration of BT has a low rate of adverse reactions and complications. However, not all patients respond to BT therapy, and large randomized controlled trials are lacking for many conditions commonly treated with BT.The local injection of BT in some conditions becomes a useful tool to decide to switch to more invasive therapies. Since 1980, the toxin has rapidly transformed from lethal poison to a safe therapeutic agent, with a significant impact on the quality of life.

Transanal surgery for obstructed defecation syndrome: Literature review and a single-center experience

Obstructed defecation syndrome (ODS) is a functional disorder commonly encountered by colorectal surgeons and gastroenterologists, and greatly affects the quality of life of patients from both societal and psychological aspects. The underlying anatomical and pathophysiological changes of ODS are complex. However, intra-rectal intussusception and rectocele are frequently found in patients with ODS and both are thought to play an important role in the pathogenesis of ODS. With the development of evaluation methods in anorectal physiology laboratories and radiology studies, a great variety of new operative procedures, especially transanal procedures, have been invented to treat ODS. However, no procedure has been proved to be superior to others at present. Each operation has its own merits and defects. Thus, choosing appropriate transanal surgical procedures for the treatment of ODS remains a challenge for all surgeons. This review provides an introduction of the current problems and options for treatment of ODS and a detailed summary of the essential assessments needed for patient evaluation before carrying out transanal surgery. Besides, an overview of the benefits and problems of current transanal surgical procedures for treatment of ODS is summarized in this review. A report of clinical experience of some transanal surgical techniques used in the authors’ center is also presented.

Semi-closed bilateral partial miotomy of the puborectalis for anismus: a pilot study: Partial miotomy of the puborectalis for anismus

BACKGROUND

Anismus or non relaxing puborectalis muscle (PRM) may cause obstructed defecation (OD). Reported surgical treatment is partial miotomy, followed by sepsis, bleeding, and incontinence. The aim of the present study was to investigate on the feasibility and outcome of a modified mini-invasive operation.

PATIENTS AND METHODS

Consecutive patients with anismus and OD not responding to medical therapy, excluding multiparous females, patients with anal incontinence, recto-rectal intussusception, and disordered psychological pattern. Semi-closed bilateral partial division of PRM, pulled down through 1-cm perianal incisions, was performed. Concomitant significant rectal mucosal prolapse and rectocele, when present, were treated. OD was evaluated using a validated score and anal/vaginal ultrasound (US) was performed pre -and postoperatively. A control group of seven patients with normal bowel habit was also investigated.

RESULTS

Eight patients (seven females), median age 48 years (range 29-71) were operated. Six also had significant mucosal prolapse and rectocele. All were followed up for a median of 12 months (range 2-40). None of them had postoperative sepsis or bleeding. One had just one occasional episode of mild anal incontinence. Symptoms improved in 6 or 75 % and, OD score decreased from 19.6 ± 1.0 to 9.2 ± 2.0 (mean ± s.e.m.), P = 0.007. No patient had anismus after surgery and PRM relaxation changed from 0 to 5.9 ± 0.8 mm being 6.6 ± 1.5 mm in controls.

CONCLUSION

Semi-closed bilateral partial division of PRM achieves muscle's relaxation on straining in all patients without any significant postoperative complication. Further studies are needed prior to consider it a validated procedure.

Treatment of gastrointestinal sphincters spasms with botulinum toxin A

Botulinum toxin A inhibits neuromuscular transmission. It has become a drug with many indications. The range of clinical applications has grown to encompass several neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum toxin A provides benefit in diseases of the gastrointestinal tract. Although toxin blocks cholinergic nerve endings in the autonomic nervous system, it has also been shown that it does not block non-adrenergic non-cholinergic responses mediated by nitric oxide. This has promoted further interest in using botulinum toxin A as a treatment for overactive smooth muscles and sphincters. The introduction of this therapy has made the treatment of several clinical conditions easier, in the outpatient setting, at a lower cost and without permanent complications. This review presents current data on the use of botulinum toxin A in the treatment of pathological conditions of the gastrointestinal tract.

Management of obstructed defecation

The management of obstructed defecation syndrome (ODS) is mainly conservative and mainly consists of fiber diet, bulking laxatives, rectal irrigation or hydrocolontherapy, biofeedback, transanal electrostimulation, yoga and psychotherapy. According to our experience, nearly 20% of the patients need surgical treatment. If we consider ODS an “iceberg syndrome”, with “emerging rocks”, rectocele and rectal internal mucosal prolapse, that may benefit from surgery, at least two out of ten patients also has “underwater rocks” or occult disorders, such as anismus, rectal hyposensation and anxiety/depression, which mostly require conservative treatment. Rectal prolapse excision or obliterative suture, rectocele and/or enterocele repair, retrograde Malone’s enema and partial myotomy of the puborectalis muscle are effective in selected cases. Laparoscopic ventral sacral colporectopexy may be an effective surgical option. Stapled transanal rectal resection may lead to severe complications. The Transtar procedure seems to be safer, when dealing with recto-rectal intussusception. A multidisciplinary approach to ODS provides the best results.

Cost considerations in the treatment of anal fissures

Anal fissure is a split in the lining of the distal anal canal. Lateral internal sphincterotomy remains the gold standard for treatment of anal fissure. Although technique is simple and effective, a drawback of this surgical procedure is its potential to cause minor but some times permanent alteration in rectal continence. Conservative approaches (such as topical application of ointment or botulinum toxin injections) have been proposed in order to treat this condition without any risk of permanent injury of the internal anal sphincter. These treatments are effective in a large number of patients. Furthermore, with the ready availability of medical therapies to induce healing of anal fissure, the risk of a first-line surgical approach is difficult to justify. The conservative treatments have a lower cost than surgery. Moreover, evaluation of the actual costs of each therapeutic option is important especially in times of economic crisis and downsizing of health spending.

Psycho-echo-biofeedback: a novel treatment for anismus--results of a prospective controlled study

BACKGROUND

Anismus or non-relaxing puborectalis muscle (PRM), detectable with anal/vaginal ultrasound (US), is a cause of obstructed defecation (OD) and may be treated with biofeedback (BFB). Many patients with anismus are anxious and/or depressed. The aim of this prospective study was to evaluate the outcome of the novel procedure psycho-echo-BFB in patients with anismus and psychological disorders.

METHODS

Patients presenting at our unit with anismus and psychological disorders between January 2009 and December 2013, and not responding to conventional conservative treatment, were enrolled in the study. All underwent four sessions of psycho-echo-BFB, carried out by two psychologists and a coloproctologist, consisting of guided imagery, relaxation techniques and anal/vaginal US-assisted BFB. A validated score for OD was used, and PRM relaxation on straining measured before and after the treatment. PRM relaxation was also measured in a control group of 7 patients with normal bowel habits.

RESULTS

Ten patients (8 females, median age 47 years, range 26-72 years) underwent psycho-echo-BFB. The OD score, evaluated prior to and at a median of 25 months (range 1-52 months) after the treatment, improved in 7 out of 10 patients, from 13.5 ± 1.2 to 9.6 ± 2.2 (mean ± standard error of the mean (SEM)), p = 0.06. At the end of the last session, PRM relaxed on straining in all cases, from 0 to 7.1 ± 1.1 mm, i.e., physiological values, not statistically different from those of controls (6.6 ± 1.5 mm). Two patients reported were cured, 3 improved and 5, all of whom had undergone prior anorectal surgery, unchanged. No side effects were reported.

CONCLUSIONS

Psycho-echo-BFB is safe and inexpensive and allows all patients with anismus to relax PRM on straining. Previous anorectal surgery may be a negative predictor.

Psycho-echo-biofeedback: a novel treatment for anismus--results of a prospective controlled study

BACKGROUND

Anismus or non-relaxing puborectalis muscle (PRM), detectable with anal/vaginal ultrasound (US), is a cause of obstructed defecation (OD) and may be treated with biofeedback (BFB). Many patients with anismus are anxious and/or depressed. The aim of this prospective study was to evaluate the outcome of the novel procedure psycho-echo-BFB in patients with anismus and psychological disorders.

METHODS

Patients presenting at our unit with anismus and psychological disorders between January 2009 and December 2013, and not responding to conventional conservative treatment, were enrolled in the study. All underwent four sessions of psycho-echo-BFB, carried out by two psychologists and a coloproctologist, consisting of guided imagery, relaxation techniques and anal/vaginal US-assisted BFB. A validated score for OD was used, and PRM relaxation on straining measured before and after the treatment. PRM relaxation was also measured in a control group of 7 patients with normal bowel habits.

RESULTS

Ten patients (8 females, median age 47 years, range 26-72 years) underwent psycho-echo-BFB. The OD score, evaluated prior to and at a median of 25 months (range 1-52 months) after the treatment, improved in 7 out of 10 patients, from 13.5 ± 1.2 to 9.6 ± 2.2 (mean ± standard error of the mean (SEM)), p = 0.06. At the end of the last session, PRM relaxed on straining in all cases, from 0 to 7.1 ± 1.1 mm, i.e., physiological values, not statistically different from those of controls (6.6 ± 1.5 mm). Two patients reported were cured, 3 improved and 5, all of whom had undergone prior anorectal surgery, unchanged. No side effects were reported.

CONCLUSIONS

Psycho-echo-BFB is safe and inexpensive and allows all patients with anismus to relax PRM on straining. Previous anorectal surgery may be a negative predictor.

Botulinum toxin injection versus lateral internal sphincterotomy for the treatment of chronic anal fissure: randomized prospective controlled trial

PURPOSE

Lateral internal sphincterotomy has been the gold standard treatment for chronic anal fissure, but it still carries the risk of permanent damage of the anal sphincter, which has led to the implementation of alternative treatment like botulinum toxin injection. The aim of this randomized prospective controlled trial was to compare the efficacy and morbidity of botulinum toxin injection and lateral internal sphincterotomy in the treatment of chronic anal fissure.

METHODS

Fifty consecutive adults with chronic anal fissure were randomly treated with either lateral internal sphincterotomy or botulinum toxin (BT) injection with 50 U BT into the internal sphincter. The complications, healing and recurrence rate, and incontinence score were assessed 2, 3, 6, 12 months after the procedure.

RESULTS

Inspection at the 2-month visit revealed complete healing of the fissure in 11 (44 %) of the patients in the BT group and 22 (88 %) of the patients in the lateral internal sphincterotomy (LIS) group (p = 0.001). At the 3-month visit, there was no significant difference between the two groups in healing. The overall recurrence rate after 6 months in the BT group was higher than in the LIS group (p < 0.05). In the 3-month follow-up, the LIS group had a higher rate of anal incontinence compared to the BT group (p < 0.05). The final percentage of incontinence was 4 % in the LIS group (p > 0.05).

CONCLUSIONS

The treatment of chronic anal fissure must be individualized depending on the different clinical profiles of patients. Botulinum toxin injection has a higher recurrence rate than LIS, and LIS provides rapid and permanent recovery. However, LIS carries a higher risk of anal incontinence in patients.

Long-term outcome of the use of botulinum toxin injection for functional anal pain

AIM

Anal pain may occur in the absence of demonstrable anal pathology. Spasm of the sphincter muscles has been suggested as a cause in some patients. We aimed to assess the effectiveness of injection of botulinum toxin in treating this condition.

METHOD

Patients who had injection of botulinum toxin over a 3-year period were identified retrospectively. Patients were excluded if anal fissure or other organic pathology was found to account for their symptoms on examination under anaesthetic. Long-term outcome was assessed at a minimum 3-year post-procedure telephone follow up.

RESULTS

Fourteen (eight male) patients were identified, of median age 50 years. Botulinum toxin (20-200 u) was injected into the internal sphincter. Seven of the 14 patients reported significant improvement in symptoms at 3 months. Seven were available for a structured telephone review at a median of 59 (42-68) months. The four patients who had benefited from the injection had remained asymptomatic.

CONCLUSION

Injection of botulinum toxin into the internal anal sphincter has a role in alleviating symptoms in a small proportion of patients with functional anal pain.

Endoscopy in the diagnosis and management of motility disorders

BACKGROUND

Gastrointestinal illness may result from either an underlying structural abnormality (e.g. neoplastic obstruction), or a functional disorder (e.g. motor diarrhea), or both (e.g. achalasia with squamous esophageal cancer).

AIMS

The purpose of this study was to highlight the potential value and role of endoscopy in the recognition and management of patients with functional and motility disorders.

METHODS

We performed a literature review in PubMed.

RESULTS

Diagnostic and therapeutic endoscopy may be under-used by motility-oriented gastroenterologists; in contrast, motility and other functional studies may be under-used by endoscopists. Yet, many areas of cross-exchange exist.

CONCLUSIONS

This review aims to guide the appropriate indications for the use of endoscopy in diagnosing and treating functional GI and motility disorders and serve as a bridge and a forum of exchange between endoscopists and motility specialists.

Botulinum toxin for recurrent anal fissure following lateral internal sphincterotomy

BACKGROUND

The aim of the study was to evaluate the efficacy of botulinum toxin injection in the treatment of recurrent anal fissure following lateral internal sphincterotomy.

METHODS

Eighty patients were treated with botulinum toxin (30 units Botox or 90 units Dysport), injected into two sites of the internal sphincter. Clinical and manometric results were recorded before and after treatment. If symptoms persisted at 2 months, the examiners could decide to re-treat the patient. The same preparation of serotype A of botulinum neurotoxin was used for reinjection.

RESULTS

One month after injection there was complete healing in 54 patients (68 per cent). Eight patients (10 per cent) reported mild incontinence of flatus that had disappeared spontaneously within 2 months. At 2 months, 59 patients (74 per cent) had a healing scar. After reinjection, 11 of 21 re-treated patients reported mild incontinence to flatus that lasted for a few weeks and resolved spontaneously. Anorectal manometry at 1 month demonstrated a significant reduction in both resting anal pressure and maximum voluntary squeeze pressure (P < 0.001). There were no relapses during a mean value of 57.9 months of follow-up.

CONCLUSION

Botulinum toxin is efficacious in patients with recurrent anal fissure following lateral internal sphincterotomy.

Botulinum toxin A for the treatment of chronic anal fissure

Since its introduction for the treatment of strabismus, botulinum toxin (BoNT) has been increasingly used in the treatment of several disorders with excessive or inappropriate muscle contractions. The therapeutic effects of BoNT occur through the temporary chemodenervation caused by the injection into the local target muscle or skin. Modulation of muscle relaxation may be achieved by varying the dose of BoNT solution injected; most adverse effects are transient. Indeed, botulinum neurotoxin has been used to selectively weaken the internal anal sphincter as a treatment for chronic anal fissure in several randomized, controlled trials and open-label studies. The use of botulinum neurotoxin seems to be an effective and safe approach for the treatment of chronic anal fissure, particularly in patients at high risk for incontinence.

Ultrasonographic patterns in patients with obstructed defaecation

BACKGROUND

Anal ultrasound is helpful in assessing organic anorectal lesions, but its role in functional disease is still questionable. The purpose of the present study is to assess anal-vaginal-dynamic perineal ultrasonographic findings in patients with obstructed defecation (OD) and healthy controls.

MATERIALS AND METHODS

Ninety-two consecutive patients (77 women; mean age 51 years; range 21-71) with symptoms of OD were retrospectively evaluated. All patients underwent digital exploration, endoanal and endovaginal ultrasound (US) with rotating probe. Forty-one patients underwent dynamic perineal US with linear probe. Anal manometry and defaecography were performed in 73 and 43 patients, respectively. Ultrasonographic findings of 92 patients with symptoms of OD were compared to 22 healthy controls. Anismus was defined on US when the difference in millimetres between the distance of the inner edge of the puborectalis muscle posteriorly and the probe at rest and on straining was less then 5 mm. Sensitivity and specificity were calculated by assuming defaecography as the gold standard for intussusception and rectocele and proctoscopy for rectal internal mucosal prolapse. Since no gold standard for the diagnosis of anismus was available in the literature, the agreement between anal US and all other diagnostic procedures was evaluated.

RESULTS

The incidence of anismus resulted significantly higher (P < 0.05) in OD patients than healthy controls on anal (48 vs 22%), vaginal (44 vs 21%), and dynamic perineal US (53 vs 22%). A significantly higher incidence of rectal internal mucosal prolapse was observed in OD patients when compared to healthy controls on both anal (61.9 vs 13.6%, P < 0.0001) and dynamic perineal US (51.2 vs.9% P = 0.001). For the diagnosis of rectal internal mucosal prolapse, anal US had a 100% sensitivity and specificity. For diagnosis of rectal intussusception, anal US had an 83.3% sensitivity and 100% specificity and perineal US had a 66.6% sensitivity and 100% specificity. In the diagnosis of anismus, anal ultrasonography resulted in agreement with perineal and vaginal US, manometry, defaecography, and digital exam (P < 0.05). Other lesions detected by US in patients with OD include solitary rectal ulcer, rectocele and enterocele. Damage of internal and/or external sphincter was diagnosed at anal US in 19/92 (20%) patients, all continent and with normal manometric values.

CONCLUSION

Anal, vaginal and dynamic perineal ultrasonography can diagnose or confirm many of the abnormalities seen in patients with OD. The value of the information obtained by this non-invasive test and its role in the diagnostic algorithm of OD is yet to be defined.

A prospective evaluation of occult disorders in obstructed defecation using the 'iceberg diagram'

OBJECTIVE

Surgical treatment of constipation and obstructed defecation (OD) carries frequent recurrences, as OD is an 'iceberg syndrome' characterized by 'underwater rocks' or occult diseases which may affect the outcome of surgery. The aim of this study was to evaluate occult disorders, in order to alert the clinician of these and minimize failures.

METHOD

One hundred consecutive constipated patients with OD symptoms, 81 women, median age 52 years, underwent perineal examination, proctoscopy, anorectal manometry and anal/vaginal ultrasound (US). Anorectal physiology and imaging tests were also carried out when indicated, as well as psychological and urogynaecological consultations. Symptoms were graded using a modified 1-20 constipation score. Both evident (e.g. rectocele) and occult (e.g. anismus) diseases were prospectively evaluated using a novel 'iceberg diagram'. The type of treatment, whether conservative or surgical, was also recorded.

RESULTS

Fifty-four (54%) patients had both mucosal prolapse and rectocele. All patients had at least two occult OD-related diseases, 66 patients had at least three of them: anxiety-depression, anismus and rectal hyposensation were the most frequent (66%, 44% and 33%, respectively). The median constipation score was 11 (range 2-20), the median number of 'occult disorders' was 5 (range 2-8). Conservative treatment was carried out in most cases. Surgery was carried out in 14 (14%) patients.

CONCLUSION

The novel 'iceberg diagram' allowed the adequate evaluation of OD-related occult diseases and better selection of patients for treatment. Most were managed conservatively, and only a minority were treated by surgery.

A prospective evaluation of occult disorders in obstructed defecation using the 'iceberg diagram'

OBJECTIVE

Surgical treatment of constipation and obstructed defecation (OD) carries frequent recurrences, as OD is an 'iceberg syndrome' characterized by 'underwater rocks' or occult diseases which may affect the outcome of surgery. The aim of this study was to evaluate occult disorders in order to alert the clinician of these and minimize failures.

METHOD

One hundred consecutive constipated patients with OD symptoms, 81 female patients, median age 52 years, underwent perineal examination, proctoscopy, anorectal manometry, and anal/vaginal ultrasound. Anorectal physiology and imaging tests were also carried out when indicated, as well as psychological and urogynaecological consultation. Symptoms were graded using a modified 1-20 constipation score. Both evident (e.g. rectocele) and occult (e.g. anismus) diseases were prospectively evaluated using a novel 'iceberg diagram'. The type of treatment, whether conservative or surgical, was also recorded.

RESULTS

Fifty-four (54%) patients had both mucosal prolapse and rectocele. All patients had at least two occult OD-related diseases, 66 patients had at least three: anxiety-depression, anismus and rectal hyposensation were the most frequent (66%, 44% and 33% respectively). The median constipation score was 11 (range 2-20), the median number of 'occult disorders' was 5 (range 2-8). Conservative treatment was carried out in most patients. Surgery was carried out in 14 (14%) patients.

CONCLUSION

The novel 'iceberg diagram' allowed the adequate evaluation of OD-related occult diseases and better selection of patients for treatment. Most were managed conservatively, and only a minority were treated by surgery.

Tratamiento de la fisura anal crónica

Chronic anal fissure is a common benign anorectal problem in Western countries that substantially impairs the patient's life. Consequently, a rapid and effective solution is required. We reviewed the various treatments for chronic anal fissure described in the literature, with the aim of establishing a therapeutic protocol. We recommend surgical sphincterotomy (preferably open or closed lateral sphincterotomy) as the first therapeutic approach in patients with chronic anal fissure. However, we prefer the use of chemical sphincterotomy (preferably botulinum toxin) in patients aged more than 50 years old and in those with previous incontinence, risk factors for incontinence (previous anal surgery, multiple vaginal births, diabetes, inflammatory bowel disease, etc.), or without anal hypertonia, despite the higher recurrence rate with medical treatments, since this procedure avoids the greater risk of residual incontinence described in the literature with surgical sphincterotomy in this group of patients.

Surgical versus chemical (botulinum toxin) sphincterotomy for chronic anal fissure: long-term results of a prospective randomized clinical and manometric study

BACKGROUND

The aim of this prospective randomized trial was to compare the effectiveness and morbidity of surgical versus chemical sphincterotomy in the treatment of chronic anal fissure after a 3-year follow-up.

METHODS

Eighty patients with chronic anal fissure were treated by whether open lateral internal sphincterotomy (group 1) or chemical sphincterotomy with 25 U botulinum toxin injected into the internal sphincter (group 2). Clinical and manometric results were analyzed.

RESULTS

Overall healing was 92.5% in the open sphincterotomy group and 45% in the toxin botulinum group (P<.001). There is a group of patients with clinical (duration of disease >12 months and presence of a sentinel pile before treatment) and manometric factors (persistently elevated mean resting pressure, % of time presence of slow waves, and number of patients or the time presence ultra slow waves after treatment) associated with a higher recurrence of anal fissure. The final percentage of incontinence was 5% in the open sphincterotomy group and 0% in the botulinum toxin group (P>.05).

CONCLUSION

We recommend surgical sphincterotomy as the first therapeutic approach in patients with clinical and manometric factors of recurrence. We prefer the use of botulinum toxin in patients older than 50 years or with risk factors for incontinence, despite the higher rate of recurrence, since it avoids the greater risk of incontinence in the surgical group.

From frown lines to fissures: Therapeutic uses for botulinum toxin

INTRODUCTION

Since the pharmacological mode of action of botulinum toxin (BTX) has been elucidated, its therapeutic potential has been increasingly recognised. The aims of this review were to summarize our current understanding of the pharmacological action of this agent and to review its therapeutic uses.

METHODS

An electronic literature search with Medline (January 1965 to December 2004) was carried out to identify articles related to the pharmacological mode of action and clinical uses for botulinum toxin using the keyword "botulinum toxin".

RESULTS AND CONCLUSION

Botulinum toxin A is emerging as a valuable clinical tool, both for diagnostic and therapeutic purposes in a wide variety of disorders, and is already the treatment of choice for selected conditions. Better understanding of its modes of action may identify alternative targets for pharmacological intervention, and may allow development of longer acting drugs with lower immunogenicity. Therapeutic uses of BTX-A must be assessed systematically in prospective studies, and the clinical role of other subtypes requires evaluation.

Treating chronic anal fissure with botulinum neurotoxin

Recent reports confirm that the management of chronic anal fissure has undergone extensive re-evaluation during the past few years. This rejuvenation of interest is attributable to the application of neurochemical treatment, which has contributed to the tendency to treat the disease on an outpatient basis. The use of botulinum neurotoxin seems to be a promising and safe approach for the treatment of chronic anal fissure, particularly in patients at high risk for incontinence. Indeed, botulinum neurotoxin has been successfully used selectively to weaken the internal anal sphincter as a treatment for chronic anal fissure. It is also more efficacious than nitrate therapy, and is not related to the patient's willingness to complete treatment.

Botulinum neurotoxin to treat chronic anal fissure: results of a randomized "Botox vs. Dysport" controlled trial

BACKGROUND

Botulinum neurotoxin induces healing in patients with idiopathic fissure. The optimal dosage is not well established.

AIM

To compare the efficacy and tolerability of two different formulations of type A botulinum neurotoxin, and to provide more evidence with regard to the choice of dosage regimens.

METHODS

Symptomatic adults with chronic anal fissure were enrolled in a randomized study. The outcome of each group was evaluated clinically, and by comparing the pressure of the anal sphincters before and after treatment.

RESULTS

Fifty patients received injections of 50 units of Botox formulation (group I), and 50 patients received injections of 150 units of Dysport toxin (group II). One month after injection, 11 patients in group I and eight in group II had mild incontinence of flatus. At the 2-month evaluation point, 46 patients in group I and 47 patients in group II had a healing scar. In group I patients, the mean resting anal pressure was 41.8% lower, and the maximum voluntary squeeze pressure was 20.2% lower, than the baseline value. In group II patients, the resting anal pressure and maximum voluntary squeeze pressure were 60.0 +/- 12.0 mmHg and 71.0 +/- 30.0 mmHg, respectively. There were no relapses during an average of about 21 months of follow-up.

CONCLUSIONS

Botulinum neurotoxin may be considered an effective treatment in patients with chronic anal fissure. The efficacy and tolerability of the two different formulations of botulinum neurotoxin were indistinguishable.

Treatment with botulinum neurotoxin of gastrointestinal smooth muscles and sphincters spasms

Local injections of botulinum neurotoxin are now considered an efficacious treatment for neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum neurotoxin provides benefit in diseases of the gastrointestinal tract. Botulinum neurotoxin inhibits contraction of gastrointestinal smooth muscles and sphincters; it has also been shown that the neurotoxin blocks cholinergic nerve endings in the autonomic nervous system, but it does not block nonadrenergic responses mediated by nitric oxide. This aspect has further promoted the interest to use botulinum neurotoxin as a treatment for overactive smooth muscles, such as the anal sphincters to treat anal fissure and outlet-type constipation, or the lower esophageal sphincter to treat esophageal achalasia. Knowledge of the anatomical and functional organization of innervation of the gastrointestinal tract is a prerequisite to understanding many features of botulinum neurotoxin action on the gut and the effects of injections placed into specific sphincters. This review presents current data on the use of botulinum neurotoxin to treat diseases of the gastrointestinal tract and summarizes recent knowledge on the pathogenesis of disorders of the gut due to a dysfunction of the enteric nervous system.